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The Yunnan University, Kunming Institute of Botany, Academia Sinica, on December 5, 1980, 1ost its staff member through 30 years and more,the Senior Professor of Plant Ecology and Geo- botany,Head of Geobotanical Laboratory, (Yun- nan University),President the Yunnan Botanical Society, Editor of Acta Botanica Yunnanica, etc  相似文献   

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本文是针对大花嵩草组的等级问题,选用了本类群和相关类群资料;应用经典植物分类学的比较方法和数字分类学的信息系统分类,相似性相关系统分类和相似性距离系统分类的方法进行研究的结。数宇分类的树系和和经典形态分类的比较表反映出它不同于蒿草属,虽然它较接近苔草属和扁穗苔属,但它们的形态性状是不相同的,所以把它作为属的等级更加合适;同时我们也同意伊万诺娃的观点。  相似文献   

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Using isotopic labelling technique (with 32P. 15N. 86Rb), we demonstrated that Gastrodia elata Bl. might draw nutrients from the soil besides their main nutritional source Armillariella mellea (Vahl. ex Fr) Karst. Hence the soil may considered as its second nutritional source.The nutritional components in the soil(fertilizer)are able to enter Gartrodia elata directly or indirectly though the mediation of Armillariella mellea. They may influence the interrelationship between Gastrodia elata and Armillariella mellea, and the growth of the former. Therefore, the study of the influence of fertilization technique on the yield and quality of Gastrodia elata is of signifi- cance.  相似文献   

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Jasmonic acid (JA) is implicated in a wide variety of developmental and physiological processes in plants. Here, we studied the effects of JA and the combination of JA and ethylenediamine-dio-hydroxyphenyl-acetic acid (EDDHA) on flowering in Lemna minor in axenical cultures. JA (0.475-47.5 nmol l(-1)) enhanced floral induction in L. minor under long-day (LD) conditions. Under the same conditions, at a concentration of 237.5 nmol l(-1), JA inhibited floral induction, and at a concentration of 475 nmol l(-1) it prevented floral induction. Under LD conditions with LD preculture, a combination of EDDHA (20,500 nmol l(-1)) and JA (47.5 nmol l(-1)) had a synergistic effect on the promotion of floral induction. Floral induction was enhanced to the greatest extent in experiments with LD precultures. Microscopic examination of microphotographs of histological sections showed that JA and, to an even greater extent, JA+EDDHA at optimal concentrations promote apical floral induction (evocation). Furthermore, JA, and to an even greater extent JA in combination with EDDHA in an optimal concentration, also promote flower differentiation, especially the development of stamens, as is evident from the microphotographs. The experimental results show that JA promotes floral induction in other species of Lemnaceae from various groups according to their photoperiodic response. The results support our hypothesis that, in addition to previously ascribed functions, JA may regulate floral induction, evocation and floral differentiation. Our hypothesis is supported also by the results obtained by quantitative determination of endogenous JA levels in L. minor at three growth stages. The levels of endogenous JA decreased from 389 ng JA g(-1) (fresh weight) of L. minor during the vegetative stage to 217 ng JA g(-1) during the evocation stage, and to 37.5 ng JA g(-1) during the flowering stage, which proves that JA is used for flowering.  相似文献   

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Plant transpiration has a key role on both plant performance and ecosystem functioning in arid zones, but realistic estimates at appropriate spatial-temporal scales are scarce. Leaf and tiller morphology and crown architecture were studied together with leaf physiology and whole plant water balance in four individual plants of Stipa tenacissima of different sizes to determine the relative influence of processes taking place at different spatial and temporal scales on whole plant transpiration. Transpiration was estimated in potted plants by leaf-level gas exchange techniques (infrared gas analyzer and porometer), by sap flow measurements, and by integrating leaf physiology and crown architecture with the 3-D computer model Yplant. Daily transpiration of each individual plant was monitored using a gravimetric method, which rendered the reference values. Leaves on each individual plant significantly varied in their physiological status. Young and green parts of the leaves showed five times higher chlorophyll concentration and greater photosynthetic capacity than the senescent parts of the foliage. Instantaneous leaf-level transpiration measurements should not be used to estimate plant transpiration, owing to the fact that extrapolations overestimated individual transpiration by more than 100%. Considering leaf age effects and scaling the estimates according to the relative amount of each foliage category reduced this difference to 46% though it was still significantly higher than gravimetric measurements. Sap flow calculations also overestimated tussock transpiration. However, 3-D reconstruction of plants with Yplant and transpiration estimates, considering both the physiological status and the daily pattern of radiation experienced by each individual leaf section within the crown, matched the gravimetric measurements (differences were only 4.4%). The complex interplay of leaf physiology and crown structure must be taken into account in scaling up plant transpiration from instantaneous, leaf-level measurements, and our study indicates that transpiration of complex crowns is easily overestimated.  相似文献   

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Bacillus subtilis spo0H gene.   总被引:16,自引:15,他引:1       下载免费PDF全文
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Tocopherols and tocotrienols are present in mature seeds. Yet, little is known about the physiological role and the metabolism of these compounds during seed development. Here we present data on tocopherol and tocotrienol accumulation during seed development in Vitis vinifera L. cv. Albert Lavallée (Royal). This species was chosen for its ability to synthesize both tocopherols and tocotrienols. It is shown here for the first time that during seed development there are significant differences in localization and accumulation kinetics of tocopherols and tocotrienols. Tocopherols are found homogeneously dispersed throughout all tissues of the seed, in concentrations ranging from 20 to 100 microg tocopherol per g dry weight. Tocopherol levels decrease gradually during seed development. In contrast, tocotrienols are only found in the endosperm of the seeds, accumulating in a sigmoid fashion during the maturation period of seed development. Tocotrienol levels were found to be (54+/-7.4) microg/g dry seed in 90-day-old seeds of V. vinifera L. Furthermore, tocotrienol biosynthesis is demonstrated in these seeds during tocotrienol accumulation and in an endosperm fraction isolated at 75 days after flowering.  相似文献   

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Common vetch (Vicia sativa L.) exploitation during middle Neolithic times in Southern France. Archaeobotanical data from Claparouse (Lagnes, Vaucluse). Beginnings of common vetch cultivation are poorly documented. Domestication could have occurred in various places. Common vetch is recorded by rare seeds in pre-Neolithic and Neolithic sites but firm evidence of cultivation does not seem available before Roman times. The Neolithic site of Claparouse is providing evidence of utilization and probable cultivation as early as some 6000 years ago. Even if this pulse is nowadays only a fodder plant, it was more likely used as human food at that time. We do not know whether it was introduced in western Europe from the Near East or locally domesticated. To cite this article: L. Bouby, V. Léa, C. R. Palevol 5 (2006).  相似文献   

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The physiological role of class III peroxidases (EC 1.11.1.7) in controlling plant growth and development has been investigated by over-expression of both native and heterologous peroxidases. However, it has remained an enigma as to why the phenotypes of different peroxidase over-expressing transgenics vary. In order to resolve the conflicting information about the consequences of peroxidase over-expression, we have explored the role of the subcellular targeting of HRP-C in controlling stem growth, root development, axillary branching and abiotic stress tolerance in tobacco (Nicotiana tabacum L.). Altering the sub-cellular targeting of vacuolar HRP-C, such that over-expressed peroxidase accumulates in the cytoplasm and cell wall, induced phenotypic changes that are typically associated with altered auxin homeostasis, and over-expression of cell wall located peroxidases. We conclude that sub-cellular targeting is a determinant of the phenotype of peroxidase over-expressing plants.  相似文献   

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BACKGROUND: Prion diseases belong to a group of neurodegenerative disorders affecting humans and animals. The human diseases include kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), and fatal familial insomnia (FFI). The pathogenic mechanisms of the prion diseases are not yet understood. Monoclonal antibodies provide valuable tools in the diagnosis, as well as in the basic research, of several diseases; however, monospecific antisera or monoclonal antibodies (mAbs) against human prion proteins were, until now, not available. MATERIALS AND METHODS: We have developed an immunization protocol based on nucleic acid injection into nontolerant PrP0/0 mice. DNA or RNA coding for different human prion proteins including the mutated sequences associated with CJD, GSS, and FFI were injected into muscle tissue. Mice were primarily inoculated with DNA plasmids encoding the prion protein (PRNP) gene and boosted either with DNA, RNA, or recombinant Semliki Forest Virus particles expressing PRNP. Hybridomas were then prepared. RESULTS: Different mAbs against human prion proteins were obtained, and their binding behavior was analyzed by peptide enzyme-linked immunosorbent assay, Western blot, immunofluorescence, and immunoprecipitation. Their cross-reactivity with prion protein from other species was also determined. Our mAbs are directed against four different linear epitopes and may also recognize discontinuous regions of the native prion protein. CONCLUSIONS: These antibodies should allow us to address questions concerning the nature of the prion protein as well as the initiation and progression of prion diseases. Moreover, these mAbs can now be used for the diagnosis of prion diseases of humans and animals.  相似文献   

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常绿杜鹃亚属Subgenus Hymenanthes是由K.Koch(1872)根据Blume(1826)建立的Genus Hymenanthes改级组合而成。但长期以来人们一直沿用了Maximowicz(1870)所建立的、后由Koehne(1893)修订过的Subgenus Eurhododendron这一亚属名称,直到最近D.F.Chamberlain(1978,1979,1982)对该亚属的名称才作了正式订正。  相似文献   

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甘肃省啮齿动物区系及地理区划的研究   总被引:10,自引:1,他引:9  
郑涛  张迎梅 《兽类学报》1990,10(2):137-144
甘肃啮齿动物有87种(含7亚种),隶2目9科41属。可将甘肃划分6个省:1.陇东高原省,有28种(含l亚种),2.中部黄土高原省,有30种;3.河西走廊省,有36种,三趾心颅跳鼠和短耳沙鼠为本省特有种;4.祁连山地省,有29种,高原高山鼠和银白高山鼠为本省特有种;5.甘南高原草原省,有34种,棕背鼾和普通田鼠为本省特有种,6.陇南山地省,有34种,豪猪和巢鼠为本省特有种。  相似文献   

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